(1) Subject to the provisions of 19-18-403, when directed by a majority vote of the members of the association, the board of trustees may invest the surplus money in the fund or any part of the surplus money in:
(a) time or saving deposits in a solvent bank, building and loan association, savings and loan association, or credit union operating in the county in which the city or town is located;
(b) bonds or other securities of the United States government; or
(c) general obligation bonds or warrants of any state, county, or city.
(2) Unless otherwise required under 19-18-403, a change in investment type is subject to a majority vote of the board of trustees of the association.